<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Homepage</title>
    <link rel="stylesheet" href="/assets/css/rule.css">
    <style>
        .rule-1 {
            background-color: red;
        }

        .rule-2 {
            background-color: yellow;
        }

        .rule-3 {
            background-color: blue;
        }

        .main-content-1 {
            font-size: 24px;
            font-weight: 600;
        }
    </style>
</head>
<body>
    <div class="main-content-1">
        <div class="rule-1">Hello, world!</div>
        <div class="rule-2">Hello, world!</div>
        <div class="rule-3">Hello, world!</div>
    </div>
    <div class="main-content-2">
        <div class="rule-4">Hello, world!</div>
        <div class="rule-5">Hello, world!</div>
        <div class="rule-6">Hello, world!</div>
    </div>
</body>
</html>